256 BULLETIN NO. VII. 



first, the rumen into which the food is taken as it is eaten. The 

 net is a shallow sack so placed that the coarse unmasticated 

 food is directed into the rumen, while after it is regurgitated 

 and finely comminuted it passes through a groove into the leaf 

 stomach and finally into the fourth compartment where the 

 gastric juice is freely mingled and the digestion proper begins. 



Intelligence is not great, as a rule in the group, the brain 

 being small and the organs of sense only moderately developed. 

 In some species which are little able to protect themselves, the 

 senses of sight and smell are highly developed and caution and 

 powers of flight supply the place of craft and other mental en- 

 dowments. The habits are comparatively uniform and are 

 chiefly interesting on account of the various ways in which they 

 are made to minister to man's necessities. 



It is almost as difficult to understand how civilized nations 

 would do without kine, sheep, goats, swine, etc. , as to imagine 

 a Laplander living without the reindeer or a desert Arab with- 

 out the camel. I need not refer to the sport furnished by the 

 various deer and antelopes the world over. 



The placenta is diffuse and the mammae are ventral or in- 

 guinal. 



The swine constitute a very old group and, like many another 

 old family, have preserved tolerably connected records from 

 the earliest times. Even in the Eocene period we find swine 

 with two hoofs (Entelodon, Choerotherium,etc.,) while in the mid 

 die Miocene members of the modern genus Sus are encountered 

 In the Eocene gypsum beds of Montmartre are four-toed swine 

 of the genera Choeropotamus and Hyopotamus. In the Miocene an 

 offshoot furnished origin to the comparatively recent family of 

 the Hippopotamidce. The genus Merycopotamus, remains of which 

 are found in India, afforded a transition to true river-horses 

 with six incisors. During the quarternary the various forms, 

 some of which were hardly larger than a hog, others larger 

 than the leviathan of the Nile, disported themselves in the 

 shallows of tHe inland seas of Europe as far as Ireland. A 

 colder period drove them across what is now the Mediterran- 

 ean and from similar causes they became extinct in India also. 

 At present, the two species are strictly confined to the con- 

 tinent of Africa. 



Two distinct geneological trees are required in the study of 

 the swine proper. In America there seems never to have ex- 

 isted any animals of the genera Sus, Porcus, or Hippopotamus 

 or even of related genera. 



